Technology update

Aug 1, 2002

Cool Chips reveals 'nanogap' manufacturing technique

Cool Chips, Gibraltar, has patented its technique for manufacturing diode devices with nanometre-wide gaps between electrodes. The company's Cool Chips products create a cooling effect by moving high-energy, or "hot", electrons across a narrow gap between two materials, in a process known as quantum mechanical electron tunnelling.

"This is a new, elegant method for manufacturing matched pairs of electrodes and maintaining a consistent gap on a nanometre scale," said Isaiah Cox, president of Cool Chips. "We are now building increasingly compact devices and are continually improving our manufacturing techniques as we drive towards commercial production prototypes."

To make the devices, Cool Chips coats an electrode with a material that will sublimate such as cadmium, and then deposits a second electrode on top. Because the cadmium layer is very thin, the upper electrode mirrors any surface variation on the lower electrode. A final heat treatment in a vacuum chamber removes the sublimative layer as a vapour, leaving a very small but constant gap between the two electrodes.

Cool Chips revealed prototypes of its devices in May of this year. The chips have potential applications in electronics, infrared sensors, computer components, refrigeration and air-conditioning: Cool Chips claims that the devices can produce cooling more efficiently than any competing technology, and are much less than one-tenth of the size and weight of compressors.